Indian Bend Wash: Construction Complete

Site Facts & Figures

This Superfund site acquired the name Indian Bend Wash because this was the principal geographic feature of the area.

IBW is one of the largest EPA sites in terms of volume of groundwater “Pump and Treat”
Through June 2006, an estimated 61.3 billion gallons of groundwater have been pumped and treated by NIBW groundwater remedy to remove an estimated 56,800 pounds of TCE.

How much water is treated at NIBW?
In 2005 we pumped and treated 16 million gallons per day or 5.8 billion gallons a year, which is enough water to fill 800 swimming pools every day or enough water to meet household needs of 40,000+ families

How much is 1 part per billion?

1 minute over past 2,000 years
~
1 inch in 16,000 miles
~
1 square of toilet paper in a roll wrapped 2¾ times around
the earth

Success at Indian Bend Wash Superfund Site

After 25 years, 61 billion gallons of contaminated water treated, and seven areas of contaminated soil addressed, the U.S. Environmental Protection Agency announced that all treatment systems needed to remove contamination at the Indian Bend Wash Superfund Site have been successfully constructed and are operating effectively.

The EPA designates sites as “construction complete” - a major milestone for the Superfund Program - when physical construction of all cleanup systems is complete, all immediate threats have been addressed and all long-term threats are under control.

Water in the Desert – A Vital Resource

The Superfund program tackles a new challenge in Arizona where water is a vital resource. Nowhere is this truer than the Indian Bend Wash Superfund Site, where residents of Scottsdale and Tempe depend on the area’s groundwater. The 13-square mile Indian Bend Wash Site, located in portions of Scottsdale and Tempe, is divided into a northern and southern area, and is one of the country’s largest groundwater cleanup sites.

Clean up of the north portion of the site in Scottsdale has centered on restoring the use of groundwater. In 2005, approximately 5.8 billion gallons of groundwater were treated- enough to fill 1,000 swimming pools every day or meet the household needs of 40,000 families.

The Site

The site was added to EPA’s national priorities list in 1983 after industrial solvents used by numerous facilities contaminated soil and groundwater with volatile organic compounds, primarily the degreasing solvent trichloroethylene, or TCE.

Central Groundwater Treatment Facility

Four groundwater treatment plants are currently operating at the site to remove VOCs from the groundwater to levels safely below the EPA drinking water standard of 5 parts-per-billion - the equivalent to a grain of sand in an olympic-size swimming pool. In almost all cases, TCE concentrations are cleaned up to non-detect levels in the groundwater. The treated groundwater is then blended into drinking water supply systems, discharged to the Salt River Project canal system, or re- injected back into the aquifer.

To date, 61 billion gallons of groundwater have been extracted to remove an estimated 57,000 pounds of VOCs at the North site. Soil cleanup is underway or complete at seven source areas to limit further TCE impacts to groundwater. The EPA expects soil cleanup to be complete within the next 5 years while the groundwater cleanup will take an additional 30 years.

Indian Bend Wash Superfund Site History

Miller Road Treatment Facility

1950s-1970s: Companies including Motorola, GlaxoSmithKline, Salt River Project, Siemens (now SMI Holding), and many other smaller companies use the chemical trichloroethylene, or TCE, as an industrial solvent in their manufacturing and operating processes. The chemical enters into groundwater.

1981: TCE is found in five municipal drinking water wells in the area. The wells are closed.

1983: The Indian Bend Wash Superfund site is listed on the U.S. EPA’s National Priorities List.

1990’s: The EPA implements cleanup strategies to address soil and groundwater contamination at the site.

Mid-1990s: Responsible companies pay for construction of four groundwater treatment plants and clean up contaminated soil. The EPA pays for additional investigation, monitoring and clean up at other areas.

Early 2000’s: The EPA further outlines cleanup strategies and performance standards to be applied to the site.

2006: The EPA announces that all physical construction of cleanup systems is complete. Soil cleanup is expected to be complete in the next five years and groundwater cleanup an additional 30 years.

Nationwide, 95 percent of all Superfund sites cleanup is underway and over 1,000 sites have construction complete.

Superfund was created in 1980 when Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act to clean up the nation's uncontrolled hazardous waste sites. Under the Superfund program, abandoned, accidentally spilled, or illegally dumped hazardous wastes that pose a current or future threat to human health or the environment are cleaned up.

The EPA works closely with communities, potentially responsible parties, scientists, researchers, contractors, and state, local, tribal, and federal authorities on site cleanup. Together with these groups, the EPA identifies hazardous waste sites, tests the conditions of the sites, develops cleanup plans, and cleans up the sites.